Content based overload protection

Unit (1, eNB, SGW, PGW) comprising a processor (20) and interface means (10) adapted for receiving and transmitting packets (15, 17) to external units (1, eNB, SGW, PGW) over a communication interface. The interface means (10) comprises a first layer filtering means (101) operating according to first level filtering rules (1010) and first packet queues (Q1_1-Q1_n); while the processor (20) comprises at least one kernel (KL_1-KL_n), second layer filtering means (102) operating according to second level filtering rules (1020), second packet queues and applications. For a given packet received on the communication interface, the unit being adapted for -delivering (12) parts the packet to the first layer filtering means (101); -applying first level filtering (14); -performing first sorting (16) and delivering parts of the packet according to the first level filtering rules (201) and delivering parts of the packet to one of the first packet queues (Q1_1-Q1_n) in dependence on the first sorting; the unit further being adapted for -delivering (16, 18) the packet to second layer filtering means (102) from kernel or from first packet queues; -applying (24) second level filtering; -performing second sorting (26) of parts of the packet according to the second level filtering rules (201) and -delivering (28) parts of the packet to one of the applications in dependence on the second sorting (AP_1-AP_n).